Multichannel recording of median nerve somatosensory evoked potentials.

OBJECTIVES: Clinical applications of multichannel (>or=64 electrodes) electroencephalography (EEG) have been limited so far. Amplitude variability of evoked potentials in healthy subjects is large, which limits their diagnostic applicability. This amplitude variability may be partially due to spatial undersampling of anatomical variations in cortical generators. In the present study, we therefore investigated whether 128-channel recordings of somatosensory evoked potentials (SEPs) can reduce this amplitude variability in healthy subjects. Additionally, we explored the relation between amplitude and age. METHODS: We recorded median nerve SEPs using a 128-channel EEG system in 50 healthy subjects (20-70 years) and compared N20, P27, and P45 amplitude as obtained with a 128-channel analysis method - based on butterfly plots and spatial topographies - and as obtained using a conventional one-cortical-channel configuration and analysis. Scalp and earlobe references were compared. RESULTS: Although amplitude variability itself was not reduced, a reduced coefficient of variation was obtained with the 128-channel method due to higher SEP amplitudes, compared to the conventional one-channel method, independent of reference. CONCLUSION: These results suggest that at the cost of some additional preparation time, the 128-channel method can measure SEP amplitude more accurately and might therefore be more sensitive to physiological and pathological changes. For optimal amplitude estimation, we recommend to increase the number of centroparietal electrodes or, preferably, to perform at least a 64-channel recording.     

Allergy to betalactam antibiotics in children: a prospective follow-up study in retreated children after negative responses in skin and challenge tests

BACKGROUND: Up to 10% of the patients in whom suspected betalactam hypersensitivity (HS) has been excluded by skin and challenge tests report suspected allergic reactions during subsequent treatments with the same or very similar betalactams. It has been suggested that the reactions may result from a resensitization induced by the challenge performed at the time of the allergological work-up. However, most patients did not undergo a second allergological work-up, to determine if the reactions resulted from betalactam HS or not. OBJECTIVES: We aimed to determine if children diagnosed nonallergic to betalactams have tolerated subsequent treatments with the initially suspected and/or other betalactams, and, in case of a reaction, if the reaction resulted from betalactam HS. Methods: We sent a questionnaire concerning the clinical history of their children to the parents of 256 children previously diagnosed nonallergic to betalactams. A second allergological work-up was performed in the children reporting suspected allergic reactions during subsequent treatments with the same and/or other betalactams. Skin tests were performed with the soluble form of the suspected (or very similar) betalactams and other betalactams from the same and other classes. Skin test responses were assessed at 15-20 min (immediate), 6-8 h (semi-late) and 48-72 h (late). Oral challenge (OC) was performed in children with negative skin tests, either at the hospital (immediate and accelerated reactions), or at home (delayed reactions). RESULTS: A response was obtained from 141 children (55.3%). Forty-eight (34%) of those children had not been treated with the betalactams for whom a diagnosis of allergy had been ruled out previously. Seven (7.5%) of the 93 children who had been treated again reported suspected allergic reactions. Skin tests and OC were performed in six of those children, and gave negative results in five children. In one child previously diagnosed nonallergic to amoxicillin associated with clavulanic acid, we diagnosed a delayed HS to clavulanic acid and a serum sickness-like disease to cefaclor. Thus, the frequency of reactions resulting from betalactam HS in children with negative skin and challenge tests is very low, and does not exceed 2.1% (2/93) if we consider that the child which refused a second allergological work-up is really allergic to betalactams. CONCLUSION: Our results in a very large number of children show that reactions presumed to result from betalactam HS are rare in children in whom the diagnosis of betalactam allergy has been ruled out previously. Moreover, they suggest that, as shown for the initial reactions, most of the reactions during subsequent treatments are rather a consequence of the infectious diseases for whom betalactams have been prescribed than a result of betalactam HS. Finally, they suggest that the risk of resensitization by OC is very low, and do not support the notion that skin testing should be repeated in children diagnosed nonallergic to betalactams.     

Transmissibility of livestock-associated methicillin-resistant Staphylococcus aureus (ST398) in Dutch hospitals

We quantified nosocomial transmission rates of sequence type (ST) 398 methicillin-resistant Staphylococcus aureus (MRSA) (an emerging livestock-associated MRSA clone) and non-ST398 MRSA isolates in patients hospitalized without infection control measures in 51 Dutch hospitals. Identification of 174 index patients initiated 139 post-exposure screenings of 9925 persons. There were 65 genotype-confirmed secondary cases (three and 62 for ST398 and non-ST398 MRSA, respectively), yielding a relative transmission risk for ST398 MRSA of 0.28 (95% CI 0.09–0.90), which was not sensitive to adjustment for duration of hospitalization at time of detection. Nosocomial transmission of ST398 MRSA is 72% less likely than that of non-ST398 MRSA strains.     

Animal Verbal Fluency and Design Fluency in school-aged children: effects of age, sex, and mean level of parental education, and regression-based normative data

The Animal Verbal Fluency (AVF) and Design Fluency (DF) structured and unstructured test versions were administered to N?=?294 healthy native Dutch-speaking children who were aged between 6.56 and 15.85 years. The AVF and DF structured test scores increased linearly as a function of age, whilst the relation between age and the DF unstructured test score was curvilinear (i.e., the improvement in test scores was much more pronounced for younger children than for older children). A higher mean level of parental education was associated with significantly higher AVF and DF structured test scores. Sex was not associated with any of the outcomes. Demographically corrected norms for the AVF and DF tests were established, and an automatic scoring program was provided.     

Hypertension management in primary care: standard care and attitude towards a disease management model

INTRODUCTION: Cardiovascular risk control has become one of the hallmarks in the treatment of diabetes and coronary heart disease, yet assessment of individual risk factors is suboptimal. We have designed a new Hypertension Screening Facility (HSF) for the evaluation of cardiovascular risk in hypertensive patients, based on 1) systematic, protocol-driven (WHO/ISH-based) analysis by nurse practitioners, 2) computer-assisted reporting of results and advice, 3) risk assessment using a Decision Support System (DSS), 4) maintenance of the autonomy of the GP. In a pilot study we wanted to investigate this HSF. METHODS: Survey 1 addressed a. how general practitioners deal with hypertension, b. whether they intend to and do use existing clinical guidelines, c. what their opinions are towards changes in the current process of care. In survey 2, we evaluated the attitude of GPs using the HSF. Responses were 43% (51 out of 120) to the first survey and 100% (20 out of 20) to the second. RESULTS: The majority of physicians included lifestyle in their assessment of risk factors and management of hypertension. Consideration of age and a positive family history was extremely high. In contrast, vision disturbances, ECG and microalbuminuria were not often considered. In the absence of additional risk factors, drug treatment was initiated in patients with a mean systolic blood pressure of 162+/-6 over 99+/-4 mmHg. In the presence of risk factors (obesity, smoking and a positive family history of cardiovascular disease) treatment is started at an average blood pressure of 154+/-8 over 96+/-4 mmHg. Opinions towards a change in management of hypertensive patients were generally positive. The opinions about the new HSF and the cardiovascular risk were reported to the general practitioner and considered useful or very useful by 79%. CONCLUSION: The present study thus confirms that cardiovascular risk evaluation by GPs is suboptimal, but there is a positive attitude towards an improvement in their assessment by HSF. The novelty of the HSF is that it respects the autonomy of the GP and brings the expertise to the GP.